My name is Jan Tolenaar. I grew up in Leiden in the Netherlands, I studied mathematics at the university of Leiden and I live and work in Leiden.

I run a one-person, Dutch company called Tolenaar IT Services providing software development services.

My recent work involves Common Lisp, C#, MS-SQL and Yardi. My not so recent work involved teaching, embedded software and multi-platform, multi-tiered client/server development environments.

I have been working in IT as an instructor, consultant, developer and architect for several companies, such as Sperry Univac (later Unisys) and Pontis Research.

In 1973 I learned my first programming language: Algol. This was followed by Cobol, Fortran, Z80, 68000, 80x86 and Univac OS1100 assembly languages, Forth, Lisp, Pascal, Modula, PL/M, C, C++, C#, PHP, SQL, Java, Ruby, Python and even Visual Basic.

Like many programmers interested in programming languages, I wrote my share of interpreters and compilers. I did Lispkit, Forth and the Small C Compiler. First on a NASCOM II microcomputer, later on several Atari's and PC's.

My other interests are chess, bridge, carom billiard, wing chun and hiking.